Measuring the heat dissipated by a device under test is often difficult. In the past, the voltage and current supplied to the device under test were measured, thus allowing for calculation of the power supplied to the device and, therefore, the heat dissipated. Unfortunately, obtaining accurate current measurements often proves difficult and often a plurality of voltages are supplied to a single device. Accordingly, since power is the product of voltage and current, a separate current measurement needs to be obtained for each unique voltage supplied to the device.